The invention relates generally to electrostatic coating systems, and more particularly to electrostatic coating systems that dispense multi-component liquid coating materials and methods therefor.
Systems that dispense electrostatically charged and atomized coating materials from a spray applicator or other dispenser coupled to a high voltage source are known generally. The coating material is generally supplied from a supply container, which may or may not be pressurized.
Some coating materials dispensed from electrostatic systems are multi-component waterborne materials that react with each other and over time harden. The rate of reaction is generally dependent upon the properties of the components and on the temperature thereof. Upon hardening, multi-component coating materials are unsuitable for spray application by electrostatic systems and become waste. The useable liquid state of the coating material prior to hardening is known as its pot life.
An object of the present invention is to provide novel electrostatic coating systems and methods therefor that overcome problems in and improve upon the prior art.
Another object of the invention is to provide novel electrostatic coating systems and methods therefor that are economical and reliable.
Another object of the invention is to provide novel electrostatic coating systems that dispense multi-component liquid coating materials having improved pot life and methods therefor.
Another object of the invention is to provide novel electrostatic coating systems that dispense multi-component liquid coating materials supplied from pressurized supply containers and methods therefor.
Yet another object of the invention is to provide novel electrostatic coating systems that dispense multi-component liquid coating materials at relatively high voltages from a supply container and methods therefor.
Still another object of the invention is to provide novel electrostatic coating systems that dispense multi-component liquid coating materials maintained at reduced temperatures in a supply container and methods therefor.
A more particular object of the invention is to provide novel electrostatic coating systems for dispensing multi-component waterborne coating materials comprising a coating material supply container having an insulated outer portion and a coating material supply line coupled to a dispenser, a metal tube disposed in the container in contact with coating material, a first non-conductive fitting coupling a first end portion of the tube to a first opening of the container, a second non-conductive fitting coupling a second end portion of the tube to a second opening of the container, and a cooling fluid supply device coupled to the tube for supplying a cooling fluid thereto.
Another more particular object of the invention is to provide novel improvements in electrostatic coating systems that dispense multi-component liquid coating materials supplied at a high voltage from a container electrically isolated from ground, comprising a cooling fluid tube disposed in a portion of the container where at least a portion of the tube contacts coating material disposed therein, the cooling fluid tube having a first end portion coupled to a first opening in the container and a second end portion coupled to a second opening in the container, the cooling fluid tube is electrically insulated from an outer portion of the container.
Yet another more particular object of the invention is to provide novel methods for electrostatic systems comprising dispensing a multi-component waterborne coating material from a dispenser at a high voltage, supplying the multi-component waterborne coating material from a non-conductive container to the dispenser, cooling the multi-component waterborne coating material in the container by supplying a cooling fluid through a tube disposed at least partially in the multi-component waterborne material, and electrically isolating the tube from an outer portion of the container.
These and other objects, aspects, features and advantages of the present invention will become more fully apparent upon careful consideration of the following Detailed Description of the Invention and the accompanying Drawings, which may be disproportionate for ease of understanding, wherein like structure and steps are referenced generally by corresponding numerals and indicators.